package main

import "fmt"

func main() {
	nums := []int{1, 2, 3, 4, 5, 6, 7, 8, 9}
	fmt.Println(nums)
	t1(nums)
	fmt.Println(nums)
}
func t1(nums []int) {
	N := len(nums)

	for l, r := 0, N-1; l < r; l++ {
		t := nums[l]
		nums[l] = nums[r]
		nums[r] = t
		r--
	}
}
